var global_var;
global_let;
let global_let;

{
    let a = 1;
    global_var = 2;
    global_let = (b) => {
        var c;
        c;
        c = 2;
        d;
        let d = 1;
        a += 1;
        b = 2;
        return a;
    }
}

global_let = 4;
    this.a = 12;
    
    this.b = () => {
        
    }
    
    var j = [1,2,3]
j[1];
j[1] = 2;
j[4] = 2;
for (let i of j) {
    
}

class L {
    jjj = '1245'
    
    f () {
        this.jjj;
    }
}

var c = new L()
c.f()

c.f.call({jjj: 12})